Biosensors are analytical devices that are employed for the detection and transduction of biochemical interactions occurring at the sensor-liquid interface.1 Although one-use structures are common, there is significant interest in devices that produce measurable signals in a real-time, ideally label-free manner. This type of detection technology constitutes a particularly attractive analytical tool that has received increasing attention over recent years with respect to environmental,2 food,3 and drug analysis,4 detection aspects of biochemical warfare,5 and clinical diagnostics.6 However, before a biosensor can be implemented as a reliable, commercially viable diagnostic device, there are a number of requirements to be addressed. The attachment of the biosensing element to the transducer must be performed in a highly controlled fashion in terms of surface distribution and spatial orientation. Moreover, biological activity must be retained upon binding7 in order for the target analyte to interact efficiently with the surface-attached biochemical probe. Further, the device should display both high specificity and sensitivity towards the target analyte and provide reliable and reproducible results, even in the presence of potentially interfering species. The undesired “non-specific adsorption” of adversary species (as opposed to the “specific adsorption” of the target analyte) has been a common and prevailing concern with respect to the analysis of complex biological samples such as blood, serum or urine. Accordingly, considerable attention has been paid to the role of adsorption effects and surface chemistry on biosensor response.
Self-assembling monolayer (SAM) chemistry is regularly regarded as a method of choice for the quick and economical preparation of structurally well-defined and customizable thin organic surfaces.8 SAM chemistry relies on the use of linking molecules that are engineered to spontaneously form ordered molecular assemblies on solid inorganic substrates.8 Moreover, functionalizable SAMs can also be designed to immobilize, in a subsequent step, various biomolecules such as proteins,9 antibodies,10 or oligonucleotides.11 Understandably, these attractive properties have endowed SAM chemistry with a unique position for the fabrication of biosensors.12 
The conversion of biological events into measurable signals requires the development of new transducing technologies that are capable of being interfaced with appropriate surface chemistry in an intimate overall structure. Amongst the various transducing systems and devices that have been engineered, those based on acoustic wave physics that commonly rely on the unique piezoelectric properties of quartz,13,14 constitute an important, yet arguably underexploited14 technology for application in the bioanalytical field.15 
U.S. Pat. No. 7,207,222 entitled “Electromagnetic Piezoelectric Acoustic Sensor” describes a sensor that comprises a piezoelectric sensor plate spaced apart from an induced dynamic electromagnetic field, such as from an electromagnetic coil through which AC current flows. This acoustic wave device, referenced herein as EMPAS, is based on the electromagnetic excitation of higher harmonics in the piezoelectric substrate.16 In practice, EMPAS offers several major advantages over its predecessors, such as an electrode-free environment and the ability to conduct measurements at tunable, ultra-high frequencies (up to 1.06 GHz), which allows for detailed information and enhances sensitivity.17 
Following SAM formation, various biomolecules may be immobilized onto a sensor surface in a subsequent step18 in order to formulate a functionalized surface for an intended application.
It is desirable to provide a biosensor having a functionalized surface that is capable of sensing a target analyte while minimizing non-specific adsorption of adversary species found in complex biological samples.